Hamilton Joshua, Breggia Anne, Fitzgerald Timothy L, Jones Michael A, Brooks Peter C, Tilbury Karissa, Khalil Andre
Chemical and Biomedical Engineering, University of Maine, Orono, ME, United States.
CompuMAINE Laboratory University of Maine, Orono, ME, United States.
Front Oncol. 2022 Oct 18;12:991850. doi: 10.3389/fonc.2022.991850. eCollection 2022.
Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with a minority (< 10%) of patients surviving five years past diagnosis. This could be improved with the development of new imaging modalities for early differentiation of benign and cancerous fibrosis. This study intends to explore the application of a two-photon microscopy technique known as second harmonic generation to PDAC using the 2D Wavelet Transform Modulus Maxima (WTMM) Anisotropy method to quantify collagen organization in fibrotic pancreatic tissue. Forty slides from PDAC patients were obtained and eight images were captured per each tissue category on each slide. Brownian surface motion and white noise images were generated for calibration and testing of a new variable binning approach to the 2D WTMM Anisotropy method. The variable binning method had greater resistance to wavelet scaling effects and white noise images were found to have the lowest anisotropy factor. Cancer and fibrosis had greater anisotropy factors (Fa) at small wavelet scales than normal and normal adjacent tissue. At a larger scale of 21 μm this relationship changed with normal tissue having a higher Fa than all other tissue groups. White noise is the best representative image for isotropy and the 2D WTMM anisotropy method is sensitive to changes induced in collagen by PDAC.
胰腺导管腺癌（PDAC）是最致命的癌症之一，只有少数（<10%）患者在确诊后能存活五年。通过开发新的成像方式以早期区分良性和癌性纤维化，这种情况可能会得到改善。本研究旨在探索一种称为二次谐波产生的双光子显微镜技术在PDAC中的应用，使用二维小波变换模极大值（WTMM）各向异性方法来量化纤维化胰腺组织中的胶原组织。获取了40张来自PDAC患者的玻片，每张玻片上的每个组织类别拍摄8张图像。生成了布朗表面运动和白噪声图像，用于校准和测试二维WTMM各向异性方法的一种新的可变分箱方法。可变分箱方法对小波缩放效应具有更大的抗性，并且发现白噪声图像具有最低的各向异性因子。在小波尺度较小时，癌症和纤维化的各向异性因子（Fa）高于正常组织和正常相邻组织。在21μm的较大尺度下，这种关系发生了变化，正常组织的Fa高于所有其他组织组。白噪声是各向同性的最佳代表性图像，二维WTMM各向异性方法对PDAC引起的胶原变化敏感。
